PSS BELGIUM NV

A loudspeaker including: a diaphragm having a first radiating surface and a second radiating surface, wherein the first radiating surface and the second radiating surface are located on opposite faces of the diaphragm; a drive unit configured to move the diaphragm based on an electrical signal; a loudspeaker support structure, wherein the diaphragm is suspended from the loudspeaker support structure via one or more loudspeaker suspension elements. The loudspeaker support structure comprises a self-supporting porous shell which encloses a volume configured to receive sound produced by the second radiating surface, wherein at least part of the self-supporting porous shell is provided by at least one self-supporting portion of porous material having a specific airflow resistance in the range 500-10000 Pa·s/m so as to allow sound produced by the second radiating surface to exit the volume enclosed by the shell.

There is provided a loudspeaker wherein a frame is moulded with a magnet system such that the frame extends through an aperture in the magnet system. By moulding the frame to extend as a single piece through an aperture, the frame can be attached to the magnet system without glue. The aperture in the magnet system extends from one side to another. By forming the frame to extend over the opening at each side, the frame can be securely connected to the magnet system. The aperture in the magnet system extends between a first surface and a second surface. The first surface and the second surface are on opposed sides of the magnet system. By the frame extending over at least a portion of the first and second surfaces, the frame extends over the apertures and securely connects the frame and magnet system, forming a unitary part.

A shaker for transmitting vibrations has: a frame, including an application attachment surface; a magnet unit to provide a magnetic field in an air gap; a coil assembly including a voice coil mounted to a voice coil former that is attached to the frame at a voice coil former attachment surface. The voice coil former positions the voice coil in the air gap, when the magnet unit is in a rest position. The magnet unit moves along a movement axis when the shaker is activated. The magnet unit is suspended by a suspension arrangement that includes proximal and distal suspensions, wherein the proximal suspension is closer to the voice coil former attachment surface than the distal suspension when the shaker is at rest. One suspension includes an elastomeric material which resiliently stretches such that the stiffness increases as the magnet unit moves from the rest position.

A method of synthesizing an audio signal for use by a horn apparatus for a vehicle to produce an audible warning sound, wherein the audio signal contains a fundamental frequency and harmonics corresponding to the fundamental frequency. The method includes: selecting weights for each of a plurality of harmonics corresponding to a fundamental frequency; using the selected weights to synthesize a precursor audio signal from only the fundamental frequency and the plurality of harmonics; compressing the precursor audio signal one or more times to provide an audio signal which has a crest factor that is below a predetermined threshold.

A loudspeaker assembly is disclosed that includes a headrest having a front face and a rear face; a bass dipole loudspeaker mounted to the headrest, wherein the loudspeaker includes a diaphragm having first and second radiating surfaces, wherein the radiating surfaces are located on opposite faces of the diaphragm, wherein the diaphragm moves at bass frequencies such that the radiating surfaces produce sound; a bass waveguide to guide bass produced by the first radiating surface via a forward-facing opening provided by the waveguide, wherein the loudspeaker is mounted such that bass produced by the second radiating surface propagates out from the rear face and such that the first radiating surface is closer to the rear face than to the front face. The forward-facing opening is larger than the first radiating surface as projected onto a plane perpendicular to a movement axis of the loudspeaker.

A shaker for transmitting vibrations to an application has a frame; magnet unit that provides a magnetic field in a gap; coil assembly including a voice coil mounted to a former. The former is attached to the frame at a former attachment surface and configured to position the coil in the gap, when the shaker is at rest. The magnet unit moves relative to the coil along an axis when the shaker is activated by supplying current to the coil. The magnet unit is suspended from the frame by a suspension arrangement including proximal and distal suspensions which interconnect the frame and magnet unit. The proximal suspension is closer to the former attachment surface than the distal suspension when the shaker is at rest. One of the proximal and distal suspensions has a stiffness K 1 , and the other K 2 , wherein K 2 >K 1 , and the ratio K 1 /K 2 is 0.4 or less.

A bass loudspeaker system including: a housing; a first and second diaphragm; a first and second drive unit, each drive unit including a stationary part and a translatable part. The translatable part of the first drive unit is attached to the first diaphragm to form a first moving assembly suspended by a first surround and a first damper, and the translatable part of the second drive unit is attached to the second diaphragm to form a second moving assembly suspended by a second surround and a second damper. The system energises the drive units to cause the first and second moving assemblies to move along a movement axis in opposite directions to produce sound. The first surround includes an outside tab, an inside tab, and a surround body between the outside and inside tabs. The second surround includes an outside tab, an inside tab, and a surround body between the outside tab and the inside tab. The first damper-includes an outside tab attached to the housing, an inside tab attached to the first moving assembly and a damper body between the outside tab and the inside tab. The second damper includes an outside tab attached to the housing, an inside tab attached to the second moving assembly and a damper body between the outside tab and the inside tab. The width of the damper body of the first damper as measured in a direction of measurement perpendicular to the movement axis is greater than the width of the surround body of the first surround in said direction of measurement. The width of the damper body of the second damper as measured in said direction of measurement is greater than the width of the surround body of the second surround in said direction of measurement.

A loudspeaker assembly for use outdoors. The loudspeaker assembly includes: a loudspeaker, including a drive unit and a diaphragm, wherein the drive unit is configured to move the diaphragm along a movement axis, a grille, positioned in front of a front face of the loudspeaker, the grille being configured to permit sound produced by the front face of the diaphragm to pass through the grille, and to inhibit the ingress of water incident on the front face of the grille from entering into a space enclosed between a rear face of the grille and the front face of the loudspeaker.

A method for positioning a shaker in a seat includes a headrest and a backrest. The headrest has a bass loudspeaker. The shaker is positioned in the headrest. The seat is typically a seat in a motor vehicle or a seat in a theatre or a massage chair or an entertainment chair.

A method for positioning a shaker in a seat includes a headrest and a backrest. The headrest has a bass loudspeaker. The shaker is positioned in the headrest. The seat is typically a seat in a motor vehicle or a seat in a theatre or a massage chair or an entertainment chair.